This invention relates to a transferable flocked fiber design or sticker material and a method for preparing the transferable flocked fiber design or sticker material and more particularly, to a releasably flocked fiber base for the transferable flocked fiber design or sticker material and a method for preparing the releasably flocked fiber base.
There have been proposed and practically employed a variety of transferable flocked fiber design or sticker materials. Most of the releasably flocked fiber bases of the prior art transferable flocked fiber design or sticker materials have been prepared by a method which substantially comprises the steps of applying a release adhesive in a molten state to one major surface of a release support base sheet to form a release adhesive layer thereon, of releasably flocking a number of fibers to the adhesive-applied surface of the release support base sheet in substantially upright position by electrostatic action and drying the assembly to firmly hold the fibers in position to thereby provide a releasably flocked fiber base. However, the releasably flocked fiber base for a transferable flocked fiber design or sticker material prepared by the above-mentioned method has presented the following two undesirable phenomena.
The first undesirable phenomenon is that when fibers 3 are releasably flocked at one end or the base end 3a to the release adhesive layer 2 applied to one major surface of the release support base sheet 1, some of the fibers 3 tend to incline with respect to the vertical or fall down rather than extending in substantially upright position as seen in the cross-sectional view of FIG. 1.
Through extensive experiments, it has been found that this phenomenon is due to the fact that since the fibers are flocked to the adhesive layer-applied surface of the release support base 1 while the material of the adhesive layer 2 is still in its molten state, when the assembly is dried the inclined and fallen-down fibers are releasably secured to the adhesive layer in these non-upright positions.
The second undesirable phenomenon is that as clear from the cross-sectional view of FIG. 2 which shows the releasably flocked fiber base of FIG. 1 on a further enlarged scale, the base ends 3a of the flocked fibers 3 are embedded in the solidified release adhesive layer 2 in a rather great depth and surrounded by rising portions of the adhesive material.
The phenomonon is due to the facts that since the fibers 3 are electrostatically flocked to the release adhesive-applied surface of the support base sheet 1 while the material of the release adhesive layer 2 is still in the molten state, the base ends 3a of the fibers 3 invade into the adhesive layer 2 by a rather great depth and that when the fibers are flocked to the release support base sheet while the material of the release adhesive layer 2 is still in the molten state, the material of the adhesive layer rises up or builds up along the base ends 3a of the fibers 3 by the so-called capillarity to form surrounding curtains about the fiber base ends.
Thus, in order to provide a transferable flocked fiber design or sticker material having the releasably flocked fiber base produced by the prior art method described hereinabove, when a thermoplastic and pressure sensitive synthetic resin layer 4 is applied to the exposed ends of the releasably flocked fibers 3 and the thus obtained transferable flocked fiber design or sticker material is then applied to an article to be decorated with the design material such as a shirt S, there are at least the following three disadvantages.
First, even when the thermoplastic and pressure-sensitive synthetic resin layer 4 is formed at the free ends of the flocked fibers 3 of the releasably flocked fiber base, since the flocked fibers 3 extend above the release adhesive layer 2 by different distances, the free ends of the flocked fibers 3 do not lie in the same horizontal plane. This means that the free ends of some of the flocked fibers 3 do not reach are not adhered to the synthetic resin layer 4 (see FIGS. 1 and 2).
Thus, when the fibers 3 are transferred onto an article to be decorated such as a shirt S by employing the transferable flocked fiber design material or sticker A having the releasably flocked fiber base as described hereinabove incorporated therein, even if the thermoplastic and pressure-sensitive layer 4 is applied against the shirt and melted under heating and pressurization conditions so as to cause a portion of the material of the synthetic resin layer 4 to penetrate into the openings between the threads of the shirt S, the ends of some of the fibers may fail to reach the molten penetrating portion of the material of the synthetic resin layer 4. As a result, the fibers which do not reach the penetrating portion of the material of the synthetic resin layer 4 will not be transferred onto the shirt S and in an extreme case, the fibers are sparsely transferred onto the shirt S to provide an incomplete fiber transfer pattern (see FIG. 3).
Second, when the releasably flocked fiber base is coloured or printed in a desired design or pattern by means of the conventional screen printing or the like, the base ends 3a of the flocked fibers 3 are embedded deeply in the solidified release adhesive layer 2 because of the capillarity mentioned hereinabove in connection with the second phenomenon and since the base ends 3a of the fibers 3 are surrounded by the rising portions of the material of the release adhesive layer 2, the printing ink is prevented from penetrating throughout the full length of the individual fibers whereby the flocked fibers 3 cannot be satisfactorily coloured or printed. Therefore, when the fiber transfer operation is performed by the employment of the transferble flocked fiber design or sticker material having the releasably flocked fiber base including such imcompletely coloured or printed flocked fibers, there is the possibility that the fibers which are spottily coloured or printed are transferred onto the shirt S.
Third, in the transfer of the releasably flocked fibers 3 from the transferable flocked fiber design or sticker material A onto the shirt S as mentioned hereinabove, the releasably flocked fibers 3 to be transferred onto the shirt in a desired or predetermined design or pattern has to be separated promptly and easily from the sticker material A.
However, since the base ends 3a of some of the releasably flocked fibers 3 of the releasably flocked fiber base in which the above-mentioned second phenomenon occurred are embedded deeply in the solidified release adhesive layer 2 or surrounded by rising portions of the material of the release adhesive layer, when the transferable flocked fiber material A is separated from shirt S in the fiber transfer operation so as to permanently transfer and retain the fibers 3 onto and on the shirt in a desired or predetermined design or pattern defined by the colouring or printing, such fibers are firmly retained on the solidified release adhesive layer 2 or on the thermoplastic and pressure-sensitive synthetic resin layer 4, such fibers 3 break off or are pulled up by the adhesive applied base sheet 1 without being transferred onto the shirt S in the separation operation to thereby provide a sparsely transferred fiber design or pattern. Furthermore, there is the possibility that a portion of the material of the release adhesive layer 2 itself remains to adhere to the transferred fibers 3 and is transferred onto the shirt S.
Any one of the prior art release adhesives employed in a molten state for releasably flocking the fibers to the release support base sheet maintains a loose paste state for a certain period of time after the application of the adhesive to the base sheet and the formation of the release adhesive layer thereon and thus, when the fiber transfer operation is performed while the adhesive layer is in the paste state, the fiber inclination, falling down and deep embedding referred to hereinabove would occur. And when the release adhesive is left as it is to allow it to dry after the application of the adhesive, the dried adhesive has lost its original viscosity or fiber flocking function.